• DeBoo, R.F.
  Chemical Control Research Institute, Canadian Forestry Service
  

Experimental aerial applications of methomyl (0.37 kg/ha), phoxim (0.42 kg/ha) and trichlorfon (1.12 kg/ha) to white spruce (Picea glauca) plantations near Grand'Mère, Québec, indicated that single aqueous spray treatments under conditions of extreme population densities of the spruce budworm (Choristoneura fumiferana) may be inadequate to induce the high degree of foliage protection required for valuable stands. Methomyl spray induced the best levels of larval population required for valuable stands. Methomyl sprays induced the best levels of larval population reduction (88%) and defoliation (39%). Results of applications of phoxim (53% reduction, 71% defoliation) and trichlorfon (52% reduction, 59% defoliation) were considered unacceptable.